DE 10 2012 002 140 B4 discloses a method of the generic type, in particular a face milling method, for applying a surface structuring to a surface of a workpiece. Such a surface structuring or marking of the surface can serve e.g. for decorative purposes or for coding the component or workpiece by applying e.g. an image pattern and/or text pattern to the surface of the workpiece.
Here, a milling cutter or a face-milling cutter can be used on a machine tool, said cutter having e.g. an axially protruding cutting edge that is not disposed in the tool axis and rotates when the tool is rotationally driven about the tool axis. Other than in the simple face milling, the milling cutter has e.g. a tip which can be formed e.g. by a protruding cutting edge of the milling cutter, and, where appropriate, can be produced by grinding back or dismantling the other cutting edge parts.
The surface of the workpiece is structured during the face-milling process, i.e. the tool (e.g. a shank cutter or a face mill or another milling cutter) moves in a rotary cutting movement on the end side over a workpiece and in so doing is moved through one or more machine axes (linear and/or rotary axes) of the machine tool. The tip and/or protruding cutting edge of the milling cutter rotating about the tool axis is not disposed in the rotary center of the tool but further out. The precise position of the tip above the workpiece surface can be determined from the position of the tool center (e.g. the so-called tool center point) and the current angle of rotation of the tool.
If there is a short, pulse-shaped axial deflection of the tip to the front in the direction of the tool axis at positions predetermined by the desired pattern, this tool tip impresses a pixel into the workpiece surface. Owing to multiple deflections with exact positioning, it is thus possible to produce any predetermined pixel pattern (e.g. an image and/or text pattern).
However, in the prior art method according to DE 10 2012 002 140 B4, the provided dimensions of the tool head receiving the tool have to be relatively large. The described method is based on the fact that a piezo stack actuator is deflected by a rectangular pulse-shaped voltage. Since the deflection of the voltage and the length of the piezo stack are directly proportional, the tool must automatically have very large dimensions and a high power or energy has to be provided.
Furthermore, the necessary pulse-shaped voltage signals cannot be transferred by an inductive or contactless energy or signal transfer since, owing to the inductivities, the signal is always influenced. If short pulse sequences having a low frequency (about 1 to 5 kHz) are inductively transmitted, the signal is highly distorted in a disadvantageous manner on account of the high inductivities, such that the pattern or the surface structuring cannot be applied with the desired image quality. However, if slip rings are used for the signal transfer while contact is made, this is disadvantageous in industrial practice, in particular on account of the maintenance susceptibility resulting from wear and contamination.
Therefore, the prior art methods show the drawbacks of a large (and thus inconveniently dimensioned) tool head and of an energy transfer which is wire-bound (or realized by slip rings).